function [ Y ] = getYMatInObj( this, obj )
% DataPartition::getYMatInObj( this:DataPartition, 
%                              obj:meta{double, DataMatrix, DatSet} )
% 
% Description
% Find and get the mat part of the meta type labels file

switch class(obj)
    case 'double'
        Y = obj;
    case 'DataMatrix'
        Y = obj.mat;
    case 'DataSet'
        Y = obj.dmY.mat;
    otherwise
        error('BatErr: Invalid input arguments.');
end

assert(size(this.zzSeenId{1}, 2) == size(Y, 1), ...
    'BatErr: @DataPartition object MUST be suitable for $obj$.');

end
